1. doc.: IEEE 802.11-14/0811r2 SubmissionYakun Sun, et. al. (Marvell)Slide 1 Overview on RBIR-based PHY Abstraction Date: 2014-07-15 Authors: NameAffiliationsAddressPhoneemail Yakun SunMarvell Semiconductor 5488 Marvell Ln, Santa Clara, CA 95054 1-408-222-3847yakunsun@marvell.com Nihar Jindal Broadcom Ron Porat Jiayin ZhangHuawei Fei TongSamsung Wookbong LeeLG Jianhan Liu MediaTek Tianyu Wu Bin TianQualcomm Bo SunZTE Shahrnaz AziziIntel July, 2014

2. doc.: IEEE 802.11-14/0811r2 Submission Introduction Received Bit Mutual Information Rate (RBIR) ESM has been well studied for PHY abstraction [1-10]. It has been agreed to use RBIR ESM as PHY abstraction for PHY and integrated system simulation [11]. The current EMD [12] needs updates to provide RBIR PHY abstraction procedure and lookup tables. An overview on RBIR PHY abstraction is presented here. Yakun Sun, et. al. (Marvell)Slide 2 July, 2014

3. doc.: IEEE 802.11-14/0811r2 Submission RBIR ESM Function RBIR ESM is the symbol level mutual information conditioned on the M-QAM. ESM function is defined as (given the SINR for a tone) –Assuming coded modulation (CM) where U is a zero mean complex Gaussian random variable with variance 1, i.e., U~CN(0,1). RBIR is the average symbol level mutual information for a transmission of Nss spatial streams over N tones and T OFDM symbols. Yakun Sun, et. al. (Marvell)Slide 3 July, 2014

4. doc.: IEEE 802.11-14/0811r2 Submission Procedure of RBIR PHY Abstraction RBIR PHY abstraction is done by: –Step 1: Generate (both desired and interfering) channels. –Step 2: Calculate the equalizer-output SINR per spatial stream for the n-th tone/t-th OFDM symbol, SINR(i ss,n,t), i ss =1…N ss. Equalizer is MRC if Nss=1, or MMSE if Nss>1. –Step 3: Map N×T×N ss SINRs to 1 RBIR –Step 4: Reverse map 1 RBIR to 1 effective SNR Yakun Sun, et. al. (Marvell)Slide 4 July, 2014

5. doc.: IEEE 802.11-14/0811r2 Submission Procedure of RBIR PHY Abstraction (2) –Step 5: Estimate the PER for this transmission Selection of reference packet length is defined in [10]. –Step 6: Determine if this transmission is successfully received based on PER. Yakun Sun, et. al. (Marvell)Slide 5 July, 2014

6. doc.: IEEE 802.11-14/0811r2 Submission Procedure of RBIR PHY Abstraction (3) Yakun Sun, et. al. (Marvell)Slide 6 Step-by-step diagram of PHY abstraction (except for channel generation). ‒ Step 1-2 are more time-consuming and can be simplified; step 3-5 are very efficient. ‒ Note SINR per-OFDM symbol is calculated even for slow-fading channels if interference levels change across the duration of the transmission. July, 2014

7. doc.: IEEE 802.11-14/0811r2 Submission Lookup Table for RBIR ESM Real-time calculation of RBIR mapping (Φ function) is time consuming. RBIR LUT can be used in this place for quick implementation. –1 LUT for each modulation  5 LUTs for all current defined modulations. For a PHY packet with a fixed MCS, only 1 LUT is loaded for PHY abstraction (PER prediction). Yakun Sun, et. al. (Marvell)Slide 7 July, 2014

8. doc.: IEEE 802.11-14/0811r2 Submission RBIR PHY Abstraction Using LUT Yakun Sun, et. al. (Marvell)Slide 8 July, 2014

9. doc.: IEEE 802.11-14/0811r2 Submission Link Adaptation Using LUT Channel-aware link adaptation can also use RBIR-based PER prediction. –Iterate over all MCS to predict performance for each MCS via RBIR. For example, genie max-rate link adaptation: –Suppose the SINR for each tone and each OFDM symbol is known. –For mcs = 0 to 9 Step 1: Map SINRs into SNR eff for the corresponding modulation –1 out of 5 RBIR LUTs each iteration Step 2: Predict PER based on SNR eff for the corresponding MCS –1 out of 10 PER LUTs each iteration Step 3: R(mcs) = (1-PER) * rate(mcs) –Select MCS * = argmax_{mcs=0…9} R(mcs) Yakun Sun, et. al. (Marvell)Slide 9 July, 2014

10. doc.: IEEE 802.11-14/0811r2 Submission What is Needed in EMD for RBIR? LUT for RBIR ESM mapping and AWGN PER. –5 RBIR LUTs –10 PER LUTs for BCC/LDPC respectively for each reference packet length. –LUTs are provided in [14]. Yakun Sun, et. al. (Marvell)Slide 10 July, 2014

11. doc.: IEEE 802.11-14/0811r2 Submission Further Works Impact of implementation loss –Channel estimation error (e.g., [5,13]) –Impact of excessive long channels for outdoor scenarios (ISI/ICI) –Other practical impairments (CFO/timing/PN…) Yakun Sun, et. al. (Marvell)Slide 11 July, 2014

12. doc.: IEEE 802.11-14/0811r2 Submission Straw Poll Include the procedure of PHY abstraction in slide3-4 into EMD Y: N: A: July, 2014 Yakun Sun, et. al. (Marvell)Slide 12

13. doc.: IEEE 802.11-14/0811r2 Submission References 1.IEEE 802.16m-08/004r5, “IEEE 802.16m Evaluation Methodology Document” 2.3GPP TR 25.892 V2.0.0 “Feasibility Study for OFDM for UTRAN enhancement”, June 2004. 3.11-14-0117-00-0hew-PHY-abstraction-for-HEW-system-level-simulation 4.11-13-1131-00-0hew-phyabstraction-for-hew-system-level-simulation 5.11-14-0353-00-0hew-suggestion-on-phy-abstraction-for-evaluation-methodology 6.11-14-0043-02-0hew-PHY-abstraction-in-system-level-simulation-for-HEW- study 7.11-14-0335-00-0hew-instantenous-sinr-calibration-for-system-simulation 8.11-14-0581-00-00ax-further-discussion-on-phy-abstraction 9.11-14-0647-02-00ax-phy-abstraction-comparison 10.11-14-0803-01-00ax-Packet-Length-for-Box-0-Calibration 11.11-14-0585-05-00ax-phy-abstraction-types-for-11ax-system-level-simulation 12.11-14-0571-02-00ax-evaluation-methodology 13.11-14-0810-00-00ax-RBIR-based-phy-abstraction-with-channel-estimation-error 14.11-14-873-00-00ax-PHY-Abstraction-Tables-for-11ax-System-Level-Simulation Yakun Sun, et. al. (Marvell)Slide 13 July, 2014